Unmasking multiple myeloma without advanced diagnostics: a clinical case from a low-resource facility

Multiple myeloma (MM) is a malignant plasma cell disorder characterized by clonal proliferation of plasma cells in the bone marrow. It accounts for approximately 1% of all cancers and about 10% of hematologic malignancies. Diagnosing MM in low-resource settings presents unique challenges dueto restricted access to advanced diagnostic modalities. A 49-year-old male presented to the emergency department with a four-day history of hematemesis and melena. He reported progressive weight loss along with severe chest wall and back pain. On physical examination, he appeared lethargic and anemic,with hepatomegaly and localized tenderness over the chest wall and spine. Initial clinical diagnosis was upper gastrointestinal bleeding, possibly related to underlying liver cirrhosis. Laboratory investigations revealed severe normocytic normochromic anemia (hemoglobin: 6.0 g/dL), and rouleaux formation onperipheral blood smear. Serum urea and creatinine were markedly elevated (108 mg/dL and 7.18 mg/dL, respectively), along with hypercalcemia (1.76 mmol/L). Urinalysis demonstrated +2 proteinuria and granular casts. Chest X-ray revealed multiple geographic lytic lesions involving the clavicle, scapulae, and ribs. Renalultrasonography indicated chronic kidney disease. Based on the presence of all four CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) criteria and rouleaux formation, multiple myeloma was strongly suspected. The patient was managed supportively with red blood cell transfusions and symptomatictreatment. Definitive diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy-proven plasmacytoma plus evidence of one or more myelomadefining events, bone marrow plasmacytosis, and a free light chain ratio >100. Bone marrow and serum electrophoresis analysis are often not available inlow-resource settings. Referral to a tertiary center with appropriate resources was suggested, but was not feasible due to financial constraints. This case illustrates that in low-resource settings, clinical vigilance combined with basic investigations can support a presumptive diagnosis of multiple myeloma andguide appropriate referral.